The objective of this proposal is to develop an electronic, rule-based clinical decision support system (CDS-Sx) that leverages national clinical practice guidelines (CPGs) to improve cancer symptom management. Specific tasks that will be performed include: 1) create software-ready computable algorithms for managing cancer-related fatigue and constipation that have been vetted with diverse cancer care providers, 2) specify the design of the CDS-Sx to deliver the algorithms at the point of care, and 3) conduct iterative cycles of usability testing with clinicians and patients using screen prototypes. To achieve these tasks, a modified ADAPTE process, which is a replicable consensus-based methodology using expert panels, will be used to develop algorithms. CDS-Sx specifications will be developed by national experts in decision support and related standards. Existing CDS technologies will be evaluated and considered as potential CDS-Sx components. Iterative usability testing using the ?think-aloud? method and wireframe prototypes will be employed to refine algorithms and CDS-Sx prototypes for clinician and patient interfaces that can be used at the point of care to generate tailored recommendations to enhance symptom management. The results of this project will provide specifications needed to develop and test the CDS-Sx that will be scalable and sharable across the nation.